1. Field of the Invention
This invention relates to a display control system for a working vehicle having a plurality of sensors arranged on a vehicle body, a display for displaying messages on various information, and a display control device for selecting information to be displayed on the display based on information from the sensors.
2. Description of the Related Art
Techniques relating to a working vehicle having a display as noted above are disclosed in Japanese Patent Laying-Open Publications S58-26652 and S62-39716, for example. In these publications, plural types of information are displayed on one display. In the former publication, vehicle running information and alarm items are switchable for display. In the latter publication, an inspection image is displayed before an engine start, and vehicle running information after the engine start.
Taking an agricultural tractor for an example of working vehicles, one developed in recent years performs not only a lift control and rolling control of a plow, but various other controls such as a change speed control of front wheels based on a steering wheel operation and a braking control of rear wheels based on a steering wheel operation. The sensors required for the lift control of the plow, for example, may include a setter for setting a target height of the plow relative to the tractor body, a sensor for measuring a pivoting angle of a rear cover, and a sensor for measuring a height of the plow relative to the tractor body. To perform these lift controls smoothly, a conventional tractor further includes an engine speed sensor to correct the controls based on an engine speed. It is important for the display to keep displaying information on a quantity of fuel needed in time of an operation, and on a temperature of engine cooling water. In addition, the technique as disclosed in the former of the above prior art publications is useful, when a normal operation cannot be performed, to utilize the display for allowing the operator to promptly recognize the situation. The technique as disclosed in the latter prior art publication is also useful to utilize the display in inspecting and adjusting the sensors arranged on the tractor body.
The prior art noted above facilitates maintenance and inspection of the numerous sensors arranged on the tractor body, in that whether the sensors are normal or abnormal may be determined on the display screen based on the signals from the sensors. However, the display cannot be used to the extent of correcting values of the signals from the sensors. In this sense, there is room for improvement. Particularly, it is unsatisfactory that an inspection image (safety monitor screen) is always displayed immediately before an engine start, and that too many pieces of information displayed are difficult to discern.